With recent successes of three-dimensional (3D) feature length films, 3D video services are expected to soar in popularity in the entertainment and communication industries, and further, in the consumer electronics industry as more devices are designed to capture, produce, communicate, display and store such image information. For example, one application is that of conventional television using displays capable of rendering 3D imaging, e.g., as a stereoscopic image, where the display renders two views, one for each eye, so that the images are perceived as 3D. Even more sophisticated displays will be able to produce and display multiple views in such a way that the 3D image perceived by the viewer depends upon the location of the viewer with respect to the display device. As a result, a widely used video coding standard, identified as the H.264/AVC standard, has been extended to include multiview video coding (MVC).
Referring to FIG. 1, multiview video sequences are captured by multiple image capturing devices 12, 14, 16 positioned in different locations and capturing images of the subjects A, B from different angles, e.g., as each subject moves within the 3D space (along axes X, Y and Z), each with its own field of view 12a, 14a, 16a, to produce corresponding single view video signals 13, 15, 17. (As will be readily appreciated, each of these video signals 13, 15, 17 can include multiple signals. For example, each may include multiple color specific signals, such as red, green and blue, or as is more common, a luminance component signal Y, a blue difference chrominance component signal Cb and a red difference chroma component signal Cr.) Accordingly, the captured images are different representations of the same objects A, B. As a result, there is some redundancy with respect to some of the captured image information, but also complementary image information due to the different viewing angles.
Referring to FIG. 2, the multiview video signals 13, 15, 17 are encoded by a MVC encoder 18 to produce a MVC signal stream 20. Such encoders are well known in the art and can be implemented using various combinations of hardware (e.g., one or more microprocessors or other suitable processors), firmware and software.
Referring to FIG. 3, in accordance with the MVC signal standard, the imaging capturing devices (e.g., digital video cameras) 12, 14, 16 produce their signals 13, 15, 17 containing bitstreams 20, portions 22 of which represent temporally adjacent video frames, and, as between the respective signals 13, 15, 17 from the image capturing devices, 12, 14, 16, represent spatially adjacent video frames.
However, notwithstanding the anticipated popularity of 3D video applications, the fact is that many single view, e.g., two-dimensional (2D) imaging applications and display devices remain in use and are expected to continue in use for some time. Currently, the MVC standard provides backward compatibility such that a compliant decoder decodes a single view and discards the remaining data, while a compliant MVC decoder decodes all views to generate the multiview, e.g., 3D video image. It would be desirable to enhance the compatibility with single view image devices.